Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

Proefschrift Universiteit Maastricht. / Met bibliogr., lit. opg. - Met samenvatting in het Nederlands.

Proefschrift Universiteit Maastricht. / Met bibliogr., lit. opg. - Met samenvatting in het Nederlands.

INTRODUÇÃO: A Miastenia gravis (MG) é uma desordem imunológica com antígenos alvos conhecidos, com produção de anticorpos contra o receptor nicotínico de acetilcolina, AAChR e Musk, na junção neuromuscular, dificultando a transmissão do impulso nervoso e provocando fadiga e fraqueza flutuantes na musculatura ocular, facial, dos membros e respiratória. A terapêutica sintomática com inibidores de acetilcolinesterase e a etiopatogênica como a timectomia, corticosteróides, agentes citostásticos e imunoglobulinas são utilizadas e indicadas em acordo com a incapacidade e gravidade clínicas. A qualidade de vida (QV) é uma ferramenta utilizada para quantificar a eficácia e a resposta às terapêuticas adotadas, avaliar a efetividade e custos econômicos de novas estratégias terapêuticas, contribuir para planejar e aplicar os recursos para a saúde na comunidade. OBJETIVO: Avaliar a influência da terapêutica na QV e evolução clínica dos pacientes com MG. CASUÍSTICA: Foram avaliados 51 pacientes com MG, 38 submetidos a tratamento conservador e 13 timectomizados. MÉTODOS: Os instrumentos genéricos quantitativos de QV como WHOQOL, qualidade de vida relacionada à saúde (QVRS) SF-36, e depressão (BDI) foram utilizados. ESTATÍSTICA: Empregou-se análise univariada com os testes de Wilcoxon, U-Mann-Whitney, Fisher e razão de chance para avaliar a evolução clínica, a QV e QVRS e depressão; análise multivariada para a caracterização dos dois grupos de terapêutica considerando a interação de múltiplos fatores. RESULTADOS: O grupo submetido à terapêutica conservadora foi constituído por 16 pacientes do sexo masculino e 22 do feminino, com média de idade de 33,71±2,76 anos; o grupo timectomizado foi constituído por 6 homens e 7 mulheres, média de idade de 32,23±4,16 anos. Os pacientes do grupo conservador apresentaram melhora clínica estatisticamente significante (p <0,05) dos aspectos clínicos, da QV, da QVRS e depressão. Os timectomizados apresentaram melhora estatisticamente significante dos aspectos físicos e psicológicos da QV e QVRS e depressão, e melhora clínica evidente e não significante (p = 0,06). A análise multivariável mostrou r=0,65 para comparação das áreas; Wilks? Lambda para analisar as distâncias, X2 = 22,67; gl = 7; p = 0,05; as medidas centrais mostraram média = -0,42 dp = 1,0 para o grupo conservador; e média = 1,22, dp = 1,0 para o grupo timectomizado. CONCLUSÕES: Nesta amostra e no período avaliado constatamos que: 1) Os pacientes submetidos ao tratamento conservador apresentaram diferenças significantes com melhora clínica acentuada, de QV, de QVRS e depressão; 2) os timectomizados apresentaram melhora clínica, da QV e QVRS em seus aspectos físicos e psicológicos, e efetiva e significante melhora dos índices de depressão; 3) a análise multivariada revelou que a timectomia produziu efeito benéfico e significativo na recuperação da saúde e bem estar nos pacientes. / INTRODUCTION: Myasthenia gravis (MG) is an immune mediated disease with production of antibodies against post-synaptic acetylcholine receptor of neuromuscular junctions (AAChR,Musk) and orders in nervous impulse transmission. The disease´s clinical characteristics include fatigability and fluctuating weakness of voluntary muscles. Acetylcholinesterase inhibitors, thymectomy, corticosteroids, cytostatic agents and immunoglobulin are widely used and are indicated according to the patient´s disability and severity. Clinical manifestations, Quality of life (Qol), health-related (HRQol) analysis are used to evaluate response to therapy. Nowadays, Qol index is an important tool to evaluate the medical outcome, treatment efficacy, cost effectiveness and net benefit of new therapeutic strategies to determine whether their cost can be justified in the planning and application of health policies. OBJECTIVE: To evaluate the influence of conservative treatment and thymectomy on Qol and clinical response of myasthenic patients. SUBJECTS: Fifty-one myasthenic patients were chosen; 38 were submitted to conservative therapy and 13 to thymectomy. METHODS: Quantitative Qol tools such as WHOQOL, SF-36 and BDI were employed to evaluate Qol, HRQol and depression. STATISTICS: Univariate analysis by means of the Wilcoxon, U-Mann Whitney and Fisher tests, Chi-Square, odd ratio were used to follow the patient?s clinical status, evolution of Qol, HRQol and depression. Discriminant analysis was used to analyze the interation of multiple factors in the characterization of conservative and thymectomized groups. RESULTS: The conservative group of patients was constituted of 16 males and 22 females average age 33.71±2.76 years; the thymectomized group was composed of 6 males, 7 females, average age 32.23±4.16 years. Patients submitted to conservative therapy improved significantly in clinical progress, Qol, HRQol and depression. The follow-up of thymectomized patients showed a strong trend for clinical progress and significant improvement in physical and psychological Qol domains as well as in depression index. Discriminant analysis showed r = 0.65, p <0.05; Wilk?s Lambda X2 = 22.67, gl = 7; mean = -0.42, SD = 1.0 for conservative group; and mean = 1.22, SD = 1.0 for timectomized group. CONCLUSIONS: A prospective evaluation of a myasthenic patients sample revealed: 1) conservative treatment was found to have a strong and significant impact on clinical progress, Qol, HRQol and depression; 2) Thymectomy partly influenced Qol, specially physical and psychological aspects. There was also improvement in depression and clinical progress; 3) the evaluation of multiple parameters pointed to a strong and positive influence of thymectomy in the recovery of the patients.

INTRODUÇÃO: A Miastenia gravis (MG) é uma desordem imunológica com antígenos alvos conhecidos, com produção de anticorpos contra o receptor nicotínico de acetilcolina, AAChR e Musk, na junção neuromuscular, dificultando a transmissão do impulso nervoso e provocando fadiga e fraqueza flutuantes na musculatura ocular, facial, dos membros e respiratória. A terapêutica sintomática com inibidores de acetilcolinesterase e a etiopatogênica como a timectomia, corticosteróides, agentes citostásticos e imunoglobulinas são utilizadas e indicadas em acordo com a incapacidade e gravidade clínicas. A qualidade de vida (QV) é uma ferramenta utilizada para quantificar a eficácia e a resposta às terapêuticas adotadas, avaliar a efetividade e custos econômicos de novas estratégias terapêuticas, contribuir para planejar e aplicar os recursos para a saúde na comunidade. OBJETIVO: Avaliar a influência da terapêutica na QV e evolução clínica dos pacientes com MG. CASUÍSTICA: Foram avaliados 51 pacientes com MG, 38 submetidos a tratamento conservador e 13 timectomizados. MÉTODOS: Os instrumentos genéricos quantitativos de QV como WHOQOL, qualidade de vida relacionada à saúde (QVRS) SF-36, e depressão (BDI) foram utilizados. ESTATÍSTICA: Empregou-se análise univariada com os testes de Wilcoxon, U-Mann-Whitney, Fisher e razão de chance para avaliar a evolução clínica, a QV e QVRS e depressão; análise multivariada para a caracterização dos dois grupos de terapêutica considerando a interação de múltiplos fatores. RESULTADOS: O grupo submetido à terapêutica conservadora foi constituído por 16 pacientes do sexo masculino e 22 do feminino, com média de idade de 33,71±2,76 anos; o grupo timectomizado foi constituído por 6 homens e 7 mulheres, média de idade de 32,23±4,16 anos. Os pacientes do grupo conservador apresentaram melhora clínica estatisticamente significante (p <0,05) dos aspectos clínicos, da QV, da QVRS e depressão. Os timectomizados apresentaram melhora estatisticamente significante dos aspectos físicos e psicológicos da QV e QVRS e depressão, e melhora clínica evidente e não significante (p = 0,06). A análise multivariável mostrou r=0,65 para comparação das áreas; Wilks? Lambda para analisar as distâncias, X2 = 22,67; gl = 7; p = 0,05; as medidas centrais mostraram média = -0,42 dp = 1,0 para o grupo conservador; e média = 1,22, dp = 1,0 para o grupo timectomizado. CONCLUSÕES: Nesta amostra e no período avaliado constatamos que: 1) Os pacientes submetidos ao tratamento conservador apresentaram diferenças significantes com melhora clínica acentuada, de QV, de QVRS e depressão; 2) os timectomizados apresentaram melhora clínica, da QV e QVRS em seus aspectos físicos e psicológicos, e efetiva e significante melhora dos índices de depressão; 3) a análise multivariada revelou que a timectomia produziu efeito benéfico e significativo na recuperação da saúde e bem estar nos pacientes. / INTRODUCTION: Myasthenia gravis (MG) is an immune mediated disease with production of antibodies against post-synaptic acetylcholine receptor of neuromuscular junctions (AAChR,Musk) and orders in nervous impulse transmission. The disease´s clinical characteristics include fatigability and fluctuating weakness of voluntary muscles. Acetylcholinesterase inhibitors, thymectomy, corticosteroids, cytostatic agents and immunoglobulin are widely used and are indicated according to the patient´s disability and severity. Clinical manifestations, Quality of life (Qol), health-related (HRQol) analysis are used to evaluate response to therapy. Nowadays, Qol index is an important tool to evaluate the medical outcome, treatment efficacy, cost effectiveness and net benefit of new therapeutic strategies to determine whether their cost can be justified in the planning and application of health policies. OBJECTIVE: To evaluate the influence of conservative treatment and thymectomy on Qol and clinical response of myasthenic patients. SUBJECTS: Fifty-one myasthenic patients were chosen; 38 were submitted to conservative therapy and 13 to thymectomy. METHODS: Quantitative Qol tools such as WHOQOL, SF-36 and BDI were employed to evaluate Qol, HRQol and depression. STATISTICS: Univariate analysis by means of the Wilcoxon, U-Mann Whitney and Fisher tests, Chi-Square, odd ratio were used to follow the patient?s clinical status, evolution of Qol, HRQol and depression. Discriminant analysis was used to analyze the interation of multiple factors in the characterization of conservative and thymectomized groups. RESULTS: The conservative group of patients was constituted of 16 males and 22 females average age 33.71±2.76 years; the thymectomized group was composed of 6 males, 7 females, average age 32.23±4.16 years. Patients submitted to conservative therapy improved significantly in clinical progress, Qol, HRQol and depression. The follow-up of thymectomized patients showed a strong trend for clinical progress and significant improvement in physical and psychological Qol domains as well as in depression index. Discriminant analysis showed r = 0.65, p <0.05; Wilk?s Lambda X2 = 22.67, gl = 7; mean = -0.42, SD = 1.0 for conservative group; and mean = 1.22, SD = 1.0 for timectomized group. CONCLUSIONS: A prospective evaluation of a myasthenic patients sample revealed: 1) conservative treatment was found to have a strong and significant impact on clinical progress, Qol, HRQol and depression; 2) Thymectomy partly influenced Qol, specially physical and psychological aspects. There was also improvement in depression and clinical progress; 3) the evaluation of multiple parameters pointed to a strong and positive influence of thymectomy in the recovery of the patients.

published_or_final_version / abstract / Medicine / Master / Doctor of Medicine

No description available.

No description available.

La myasthénie (Myasthenia Gravis) est une maladie neuromusculaire impliquant des auto-anticorps dirigés majoritairement contre le récepteur à l’acétylcholine (RACh) et entrainant une fatigabilité musculaire. Ces auto-anticorps pathogènes sont produits principalement par le thymus qui présente une hyperplasie caractérisée par le développement de centres germinatifs ectopiques. De récentes études ont démontré la surexpression de chimiokines dans le thymus des patients et la présence anormale de vaisseaux sanguins de type HEV (cellules endothéliales à paroi haute). L’objectif de ma thèse a été de mieux comprendre les mécanismes physio-pathologiques conduisant à l’hyperplasie thymique en étudiant le rôle des chimiokines dans la myasthénie.Nous avons tout d’abord démontré que le nombre de HEV thymiques est proportionnel au degré d’hyperplasie suggérant leur implication directe dans le recrutement des cellules périphériques. En analysant les chimiokines exprimées sur ces HEV, nous observons l’expression sélective de SDF-1/CXCL12. En parallèle, la présence de lymphocytes B, de cellules dendritiques myéloïdes ou plasmacytoïdes et de monocytes/macrophages exprimant le récepteur au SDF-1, CXCR4, a été observée au niveau des HEV. En périphérie, nous montrons une diminution de l’expression de CXCR4 ainsi que du nombre de mDC et de monocytes dans le sang des patients suggérant le recrutement de ces cellules dans le thymus.Le thymus des patients myasthéniques est aussi caractérisé par une surexpression de la chimiokine CXCL13 par les cellules épithéliales thymiques. Pour mieux comprendre les mécanismes conduisant à l’hyperplasie thymique, nous avons développé un modèle de souris transgéniques avec surexpression thymique de CXCL13. Dans le thymus de ces souris, nous observons une surexpression de CXCL13 et une augmentation de nombre de lymphocytes B, notamment pour les souris jeunes. Nous étudions maintenant si l’immunisation de ces souris avec du RACh purifié induit une myasthénie expérimentale associée à une hyperplasie thymique ; un nouveau modèle animal de la maladie qui se rapprocherait mieux de la pathologie humaine.Dans la myasthénie, le thymus est aussi caractérisé par une signature inflammatoire, avec notamment une surexpression d’interféron de type I (IFN-I). Nous démontrons que le Poly(I:C), une molécule mimant les effets des ARN double-brin, induit spécifiquement la surexpression du RACh-α par les cellules épithéliales thymiques humaines via la libération d’IFN-I. L’IFN-I entraine aussi la surexpression des chimiokines CXCL13 et CCL21 comme dans le thymus des patients myasthéniques. Chez des souris C57Bl6, mais pas chez des souris KO pour le récepteur à l’IFN-I, des injections de Poly(I:C) entrainent des modifications thymiques avec une surexpression spécifique de RACh-α, d’IFN-I et de chimiokines. En périphérie, ces injections entrainent l’apparition dans le sérum d’anticorps contre le RACh-α spécifiques de la myasthénie.L’ensemble de ces résultats suggère que dans le thymus des patients myasthéniques, le développement anormal de HEV exprimant du SDF-1 et la surexpression de CXCL13 joueraient un rôle central dans le recrutement de cellules périphériques. Ces cellules, une fois dans l’environnement inflammatoire caractéristique du thymus myasthénique, pourraient alors développer une réaction auto-immune contre le RACh. De nouvelles molécules thérapeutiques contrôlant l’expression de ces chimiokines ou l’angiogenèse pourraient diminuer le développement de l’hyperplasie thymique et éviteraient la thymectomie ou l’utilisation des glucocorticoïdes par les patients atteints de myasthénie. / Autoimmune myasthenia gravis (MG) is a muscular disease mediated by autoantibodies, mainly directed against the acetylcholine receptor (AChR). The pathogenic antibodies are especially produced in the thymus, which is often characterized by a hyperplasia with germinal centers. Recent studies demonstrated the overexpression of chemokines and the abnormal development of high endothelial venules (HEV) in the MG thymus. The aim of my thesis was to better understand the mechanisms that lead to thymic hyperplasia in MG by analyzing the role of chemokines in peripheral cell recruitment. We demonstrated that the number of HEVs correlated with the degree of hyperplasia suggesting a direct link between HEVs and peripheral cell recruitment. To define its mechanism of action, we examined which chemokines were expressed on thymic HEVs. We uniquely detected SDF-1 and observed that B cells, myeloid dendritic cells (mDCs), plasmacytoid DCs and monocytes/macrophages that expressed the SDF-1 receptor CXCR4 localized inside and around thymic HEV. In parallel we observed a decreased CXCR4 expression and a decreased number of mDCs and also monocytes in the periphery suggesting their recruitment to the MG thymus. As the MG thymus was recently characterized by the overexpression of CXCL13 in thymic epithelial cells (TECs), we investigated its contribution to thymic hyperplasia. We therefore generated a transgenic mouse model overexpressing in medullary TECs CXCL13 under the control of keratin 5. We demonstrated that transgenic K5-CXCL13 mice specifically overexpressed CXCL13 in the thymus, while no other tested chemokines were upregulated. Preliminary results showed that elevated levels of CXCL13 resulted in an increased number of B cells in the thymus of transgenic mice, which localized preferentially in loose aggregates in medullary areas. We are presently investigating if immunization with purified AChR induces experimental MG with thymic hyperplasia in these mice. Myasthenic mice with a hyperplastic thymus could present a new animal model for MG with a phenotype that is closer to the human disease than the current MG model. As the hyperplastic MG thymus displays the hallmarks of a viral signature, we investigated the effect of pathogen-associated molecules on thymic changes associated with MG. We demonstrated that dsRNA signaling induced by Poly(I:C) specifically triggers the overexpression of α-AChR in human TECs through the release of IFN-I. We also observed that IFN-I was able to upregulate CXCL13 and CCL21, similarly to what is observed in the MG thymus. In addition, Poly(I:C) injections in wildtype mice, but not in IFN-I receptor KO mice, specifically increase thymic expression of α-AChR and, in parallel, CXCL13 and CCL21 expression. In periphery, Poly(I:C) even induced an anti-AChR autoimmune response characterized by a significant production of serum anti-AChR antibodies and a specific proliferation of B cells. Overall the results obtained in the course of my PhD showed that the abnormal development of SDF-1-expressing HEVs and the CXCL13 overexpression play a central role in the recruitment of peripheral cells to the MG thymus. Once these cells have arrived in the inflammatory environment, which is characteristic for MG, they could develop an autoimmune reaction against AChR. New therapeutic molecules that control chemokine expression and angiogenic processes could diminish the development of thymic hyperplasia and avoid thymectomy or the use of corticoids.

No description available.